1. Field of the Invention
The present invention relates to the structure of a high-temperature regenerator for an absorption type chiller heater.
2. Detailed Description of the Prior Art
Conventionally, a system referred to as an absorption type chiller heater or an absorption type refrigerator comprises a high-temperature regenerator, in which a dilute absorbent liquor flowing in from an absorber is heated to boil so that refrigerant vapor is isolated therefrom. The dilute absorbent liquor is composed of an absorbent, such as a lithium bromide (LiBr) aqueous solution (containing a surface-active agent), and a large amount of refrigerant such as water.
Conventional high-temperature regenerators use combustion gas introduced from a dedicated burner as their heat sources. Some high-temperature regenerators may use high-temperature exhaust gas that is generated and introduced from outside the absorption type chiller heaters, for example, from a gas turbine for use in power generation or the like.
FIGS. 4(A) and 4(B) show a direct-fired type high-temperature regenerator, one of the former high-temperature regenerators.
Specifically, the high-temperature regenerator 1 comprises an outer shell 3 and an inner shell 5 penetrating through the outer shell 3. This inner shell 5 has a sideways U shape with both ends 7 and 9 located outside the outer shell 3. Of these ends 7 and 9, the lower end 7 has a burner 11 mounted thereon. An exhaust duct 13 is attached to the upper end 9.
Combustion gas 14 introduced from the burner 11 is let through a combustion gas flue 6 constituted inside the inner shell 5. A dilute absorbent liquor 15 introduced to between the outer and inner shells 3 and 5 comes into contact with the inner shell 5, i.e., the combustion gas flue 6, so that the liquor 15 is heated to boil, isolating refrigerant vapor therefrom. The isolated refrigerant vapor 17 is collected to a refrigerant vapor collecting hole 19, and then introduced to a not-shown low-temperature regenerator.
As shown in FIGS. 5(A) and 5(B), the inner shell 5 sometimes constitutes a horizontal, straight-shaped combustion gas flue 6 with both ends 7 and 9 located outside the outer shell 3. Here, the burner 11 is attached to the right end 7 in FIG. 5(A), and the exhaust duct 13 is connected to the left end 9.
In a high-temperature regenerator using exhaust gas as its heat source, the capacity of the exhaust gas determines the operational capacity of the absorption type chiller heater. In other words, the capacity control is confined within the control range of the turbine. Current gas turbines are typically high in partial load limit, with the very minimum of 50% or so.
In such a high-temperature regenerator using exhaust gas as the heat source, capacity control can also be made by arranging a valve for intercepting the exhaust gas at the portion where the exhaust gas is introduced into the high-temperature regenerator, and adjusting the opening of the valve so as to allow heat input as much as required in the high-temperature regenerator. This valve, however, is expensive since it requires excellent interception performances and a high degree of reliability.
Alternatively, a high-temperature regenerator using combustion gas from a burner as its heat source may be provided along with the high-temperature regenerator using exhaust gas as its heat source. In this case, a valve on a dilute absorbent liquor pipe is switched to put the former high-temperature regenerator into exclusive use when the absorption chiller heater operates under lower loads, and to activate both high-temperature regenerators under higher loads. This configuration, however, requires a wider floor space and complicated piping. Here, an increase in running cost is also expected.